Method of making multiply trays



Feb. 11, 1941. J. A. PQTCHEN 2,231,345

mmaon OF MAKING MULTIPLY TRAYS Filed Dec. 5, 1938 Patented Feb. 11, 1941 V UNITED STATES METHOD or MAKING MULTIPLY TRAYS Joseplt'A. Potchen, .Grand Rapids, Mich assignor to Haskelite Manufacturing Corporation, a

corporation of New York Application December 5, 1938, Serial No. 243,924

3 Claims.

Decorative panels both fiat and in the form of trays or thelike, are commonly composed of plywood, the facing plies of wh ch are usually veneers of the rarer, more expensive woods. The object of the present invention is to produce a satisfactory product of this kind which shall cost very much less than the usual plywood devices. In carrying out my invention, I substitute for the usual face'veneers, sheets of fibrous material, 0 usually paper. Therefore, viewed in one of its aspects, the present invention may be said to have for its object to produce a simple and novel multiply panel having decorative or ornamental facings of paper or the like.

In order to reduce the cost of manufacture of multiply trays, it is desirable that the bonding of the core and face members he carriedout simultaneously with the molding of the parts into the desired shapes. When the bonding and the molding is effected by pressing an assembly of plies between dies, some parts of the paper for the upper or inner side of, the tray are under compression while other parts are in tension. While the proper kinds of paper stretch sufliciently to prevent ruptur'e of the paper during molding,paper does not compress readily and, therefore, wrinkles form in areas, such as those at the corners of a cornered tray, where the need for compression is considerablei i A further object of the present invention is to make it possible to manufacture a tray faced with paper or other fibrous material without creating wrinkles in the facings.

In carrying out the last-mentioned object of my invention, I so shape the mold or die faces in the areas where the paper is subjected to the greatest amount of compression with ridges or ribs so disposed that, instead of compressing, the paper may take a more or less sinuous shape that eliminates wrinkling and adds to the ornamental appearance of the tray.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with'particularity in the claims; but,

for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein: Figure 1 is a top plan view of a tray embodying the present invention; Fig. 2 is a view similar to Fig. l, on a'much larger scale, and showing only a corner of the tray; Fig. 3 is a. section on line 3--3 of Fig. 2', but on a. larger scale; Fig. 4 is a section on line 4-4 of Fig. 2; Fig. 5 is a perspective view of a fragment of one of the facing sheets ready to be applied to a core for the making of a panel: Fig. 6 is a moreor less diagrammatic view showing a pair of cooperating die members, two facing sheets and a core member adapted to form anassembly for a tray, all separated from each other, but arranged in the order in which they appear at the beginning of a bonding and molding operation; Fig. 'l is-a bottom view of one-half of the upper die member shown in Fig. 6; Fig. 8 is a top view-of one-half of the lower die member 10 of Fig. 6; and Fig; 9 is a section on a greatlyenlarged scale on line 9-8 of Fig. 7. r l ,In the drawing I have illustrated my invention as applied to a tray, and the method of manufacturing the same, and thedetailed description 15 will be confined to this particular embodiment, since it will be evident thatflat panels can be produced in the same way, except that no molding is required and flat pressure plates or platens may be employed instead of dies to effect the bonding. The tray is composed of three separate'layers, namely a core layer I, an upper facing layer 2, and an under facing layer 8. The layer I may be a pieceof woodveneer or a piece of thin, inex-' pensive plywood, whereas the layers 2 and 3 are 25 sheets of paper. It is my purpose that the tray shall be complete, except for edge trimming, upon the bonding together and the molding of 'the three layers, so that no subsequent finishing operations are needed to place a tray in condition so for use. When the core member is to be composed of a plurality of plies, these plies may be bonded togetheras a preliminary step, or the bonding thereof may occur simultaneously with the bonding of the core to the facing members. Therefore, 35 as a preliminary step, I decorate the surface of each facing-sheet that is exposed when the tray has been made, if decoration is desired, and coat that surface with a lacquer; both pigments and lacquer being chosen. for their ability not to fade or disintegrate at subsequent curing temperatures of from 200 F. to 300 F. Thus, I am enabled to apply the decorations and the lacquers by a rolling process. By a similar process, the opposite side 45 of the paper is coated with an adhesive material, preferably of the artificial resin type. In this way the decorative and protective coatings for the tray and the glue coatings to effect the bonds between the layers and the tray are not only applied so rapidly, but uniformity of distribution of the coating materials and avoidance of an accessible amount of such materials results.

After the coatings on the paper, including the glue coatings, have become dry, two paper facings as and' a' core-member. are assembled and the bonding and imoldlng opera'tion lis vcarried out.

"mingfiatherezissshown:one'ot:thafa'cing sheets Jhavingson TOITG'FSIIITREG or side the finishing :coat

' =or:coats -kand zon the othenside a glue'coating "5.

'iInimaking thexassembly of the several layers, the

.glue-coatings *oi :the vfacing sheets are, of course,

.lai'da'against:thefaceszo'f thecoremember I The asseniblyiis I thengplaced between male and female .dies,--6 and '21 respectively, which provide a die cavity which corresponds to the shape of thetray to 'be-produced. The-dies are closed so .as to exert the necessary pressureon the-assemblyfor 1the trayrto i moldltheilatter .into tray dorm, and

fthemdies are .heated in any suitable way, :not

shown, toecure =the-glue.

'Theitray illustrated?is-substantiallyrectangular andsh'asssloping side walls whichimeetraatth'e' four "corners: of the tray. "Thepaper of the upper::fac-

meet-each other,x=.butrare separated by a fiat strip :or band '8-'extending from the bottom of the tray to the top. The female member of thevdie has flattened corner sections 9 and the male die mem- :'.ber has .iflattened scorners i; thenflattened portions. 3-8 'of .the .panel 'b'eingiformed between the :complementary rdie ffaces llrand I 0.

.It rislnot :sufii'cient *to .make .the corners. hat,

;but room =must-still be provided "to accommate the excess paperrstockewhich:would otherwise developr wrinkles'iin'.these areas. I have found that if z'thefaces ll!) of the 'maleidie member are pro- "vide'd -with shallowsribs I lextending parallel' with each other E'from gpoints near the bottom of the tray .to :the t'op, so as to produce a corrugated eefiectron the .paper, :the excess paper stock which would otherwiseacreate awrinkles taken up in these l corrugations, indicated -:at 12, so What not only are. awrinkleszsavoided, .but decorative ridges are developediinrth-e nornersxof the tray without :unduestretching: of thejpaper.

:By properly choosing the facings of paper or other =fibrous :materials, and' the pigments and lacquers as well asstheadhesivesa panel containing-aniinexpens'ive r core:may be. manufactured at .a :cost which is "only 7 a *small fraction of the cost of :a. similar panel "composed entirely of plywood c and, at the same time,. my :panel will be as :attractiveandsserviceable as :theother. A- great advantageriseattainediin-themanufacture of trays :becausetofitheifactzthat'aatray is complete, except 'for' edge strimming, upon leaving the molds or dies, "and athe zfurtherfifact that the pigments, 'lacquers and-gluesqcanzallfbetapplied tothe paper ifacingnnaterial f by means of rollers, whereby a minimum :amountoflmaterial is used and the :zcostoiaappli-cationo'fithe materials to the facings ais insigni'ficant. It will .also be seen that my enhances the appearance of the trays, butavoids theconsiderable loss that would otherwise occur because of wrinkling to such an extent as to make it unnecessary to discard a substantial percentage of trays.

I claim:

1. The method of making a multiply trayhaving a bottom and sides inclined thereto, said sides meeting in corners, which comprises coating flexible fibrous sheet material with an adhesive substance, permitting the adhesive to dry, assembling two pieces of such coated fibrous material with their adhesive-coated faces toward each other anda fiat core 'memberinterposed.between the same, pressing the assembly together and molding itinto the desired shape under conditions to bond the whole together, andduring the molding operation, corrugating the fibrous material .in the corners on the inner side of the tray from the bottom to the rimin directions tooflset the tendency to wrinkle under molding forces that place the said sheet material under compression in the tray corners.

2. The method of making a multiply tray having a bottom and sides inclined thereto-said sides meeting in corners, which comprises coating one face of a flexible fibroussheet material with a finishing layer of lacquer and the-other face with an adhesive substance that requires heat and pressure to set the same, permitting the lacquer and the adhesive to dry, assemblingtwo pieces 01 such coated fibrous material with their adhesivecoated faces toward each other and a flat core member interposed between the same, pressing and heating the assembly to bond the plies .together and mold the panel into the desired shape, and during the molding, corrugating thepaper in the corners on the inner side of the tray-from the bottom to the rim where the fibrous material is under compression.

3. The method of making a multiply tray having a bottom and sides inclined thereto, said sides'meeting in corners, which comprises coating one face of aflexible fibrous sheet material with a flnishing layer'of lacquerrand the other face with an adhesive substance that requires heat and pressure .toset the same, permitting the lacquer andthe adhesive to dry, assembling two pieces of such coated fibrous material with their adhesivecoated faces toward each other and a thin, fiat,

wood core member interposed between the same,

pressing and heating the assembly to bond'the plies together and mold'the panel into the desired shape, and during themolding, compressing the wood on the inner side-of the tray .at the corners to produce corrugations extending from the bottom of the tray to the rim and compelling the inner or top layer of fibrous sheet material to follow the contours of such corrugations.

JOSEPH A. POTCHEN. 

